<html>

<head>
	<title>粒子效果</title>
	<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
</head>

<body style="">
	<div id="jsi-particle-container" class="container"><canvas width="932" height="377"></canvas></div>
	<style>
		html,
		body {
			width: 100%;
			height: 100%;
			margin: 0;
			padding: 0;
			overflow: hidden;
		}

		.container {
			width: 100％;
			height: 100%;
			margin: 0;
			padding: 0;
			background-color: #000000;
		}
	</style>

	<script>
		var RENDERER = {
			PARTICLE_COUNT: 1000,
			PARTICLE_RADIUS: 1,
			MAX_ROTATION_ANGLE: Math.PI / 60,
			TRANSLATION_COUNT: 500,

			init: function (strategy) {
				this.setParameters(strategy);
				this.createParticles();
				this.setupFigure();
				this.reconstructMethod();
				this.bindEvent();
				this.drawFigure();
			},
			setParameters: function (strategy) {
				this.$window = $(window);

				this.$container = $('#jsi-particle-container');
				this.width = this.$container.width();
				this.height = this.$container.height();

				this.$canvas = $('<canvas />').attr({ width: this.width, height: this.height }).appendTo(this.$container);
				this.context = this.$canvas.get(0).getContext('2d');

				this.center = { x: this.width / 2, y: this.height / 2 };

				this.rotationX = this.MAX_ROTATION_ANGLE;
				this.rotationY = this.MAX_ROTATION_ANGLE;
				this.strategyIndex = 0;
				this.translationCount = 0;
				this.theta = 0;

				this.strategies = strategy.getStrategies();
				this.particles = [];
			},
			createParticles: function () {
				for (var i = 0; i < this.PARTICLE_COUNT; i++) {
					this.particles.push(new PARTICLE(this.center));
				}
			},
			reconstructMethod: function () {
				this.setupFigure = this.setupFigure.bind(this);
				this.drawFigure = this.drawFigure.bind(this);
				this.changeAngle = this.changeAngle.bind(this);
			},
			bindEvent: function () {
				this.$container.on('click', this.setupFigure);
				this.$container.on('mousemove', this.changeAngle);
			},
			changeAngle: function (event) {
				var offset = this.$container.offset(),
					x = event.clientX - offset.left + this.$window.scrollLeft(),
					y = event.clientY - offset.top + this.$window.scrollTop();

				this.rotationX = (this.center.y - y) / this.center.y * this.MAX_ROTATION_ANGLE;
				this.rotationY = (this.center.x - x) / this.center.x * this.MAX_ROTATION_ANGLE;
			},
			setupFigure: function () {
				for (var i = 0, length = this.particles.length; i < length; i++) {
					this.particles[i].setAxis(this.strategies[this.strategyIndex]());
				}
				if (++this.strategyIndex == this.strategies.length) {
					this.strategyIndex = 0;
				}
				this.translationCount = 0;
			},
			drawFigure: function () {
				requestAnimationFrame(this.drawFigure);

				this.context.fillStyle = 'rgba(0, 0, 0, 0.2)';
				this.context.fillRect(0, 0, this.width, this.height);

				for (var i = 0, length = this.particles.length; i < length; i++) {
					var axis = this.particles[i].getAxis2D(this.theta);

					this.context.beginPath();
					this.context.fillStyle = axis.color;
					this.context.arc(axis.x, axis.y, this.PARTICLE_RADIUS, 0, Math.PI * 2, false);
					this.context.fill();
				}
				this.theta++;
				this.theta %= 360;

				for (var i = 0, length = this.particles.length; i < length; i++) {
					this.particles[i].rotateX(this.rotationX);
					this.particles[i].rotateY(this.rotationY);
				}
				this.translationCount++;
				this.translationCount %= this.TRANSLATION_COUNT;

				if (this.translationCount == 0) {
					this.setupFigure();
				}
			}
		};
		var STRATEGY = {
			SCATTER_RADIUS: 150,
			CONE_ASPECT_RATIO: 1.5,
			RING_COUNT: 5,

			getStrategies: function () {
				var strategies = [];

				for (var i in this) {
					if (this[i] == arguments.callee || typeof this[i] != 'function') {
						continue;
					}
					strategies.push(this[i].bind(this));
				}
				return strategies;
			},
			createSphere: function () {
				var cosTheta = Math.random() * 2 - 1,
					sinTheta = Math.sqrt(1 - cosTheta * cosTheta),
					phi = Math.random() * 2 * Math.PI;

				return {
					x: this.SCATTER_RADIUS * sinTheta * Math.cos(phi),
					y: this.SCATTER_RADIUS * sinTheta * Math.sin(phi),
					z: this.SCATTER_RADIUS * cosTheta,
					hue: Math.round(phi / Math.PI * 30)
				};
			},
			createTorus: function () {
				var theta = Math.random() * Math.PI * 2,
					x = this.SCATTER_RADIUS + this.SCATTER_RADIUS / 6 * Math.cos(theta),
					y = this.SCATTER_RADIUS / 6 * Math.sin(theta),
					phi = Math.random() * Math.PI * 2;

				return {
					x: x * Math.cos(phi),
					y: y,
					z: x * Math.sin(phi),
					hue: Math.round(phi / Math.PI * 30)
				};
			},
			createCone: function () {
				var status = Math.random() > 1 / 3,
					x,
					y,
					phi = Math.random() * Math.PI * 2,
					rate = Math.tan(30 / 180 * Math.PI) / this.CONE_ASPECT_RATIO;

				if (status) {
					y = this.SCATTER_RADIUS * (1 - Math.random() * 2);
					x = (this.SCATTER_RADIUS - y) * rate;
				} else {
					y = -this.SCATTER_RADIUS;
					x = this.SCATTER_RADIUS * 2 * rate * Math.random();
				}
				return {
					x: x * Math.cos(phi),
					y: y,
					z: x * Math.sin(phi),
					hue: Math.round(phi / Math.PI * 30)
				};
			},
			createVase: function () {
				var theta = Math.random() * Math.PI,
					x = Math.abs(this.SCATTER_RADIUS * Math.cos(theta) / 2) + this.SCATTER_RADIUS / 8,
					y = this.SCATTER_RADIUS * Math.cos(theta) * 1.2,
					phi = Math.random() * Math.PI * 2;

				return {
					x: x * Math.cos(phi),
					y: y,
					z: x * Math.sin(phi),
					hue: Math.round(phi / Math.PI * 30)
				};
			}
		};
		var PARTICLE = function (center) {
			this.center = center;
			this.init();
		};
		PARTICLE.prototype = {
			SPRING: 0.01,
			FRICTION: 0.9,
			FOCUS_POSITION: 300,
			COLOR: 'hsl(%hue, 100%, 70%)',

			init: function () {
				this.x = 0;
				this.y = 0;
				this.z = 0;
				this.vx = 0;
				this.vy = 0;
				this.vz = 0;
				this.color;
			},
			setAxis: function (axis) {
				this.translating = true;
				this.nextX = axis.x;
				this.nextY = axis.y;
				this.nextZ = axis.z;
				this.hue = axis.hue;
			},
			rotateX: function (angle) {
				var sin = Math.sin(angle),
					cos = Math.cos(angle),
					nextY = this.nextY * cos - this.nextZ * sin,
					nextZ = this.nextZ * cos + this.nextY * sin,
					y = this.y * cos - this.z * sin,
					z = this.z * cos + this.y * sin;

				this.nextY = nextY;
				this.nextZ = nextZ;
				this.y = y;
				this.z = z;
			},
			rotateY: function (angle) {
				var sin = Math.sin(angle),
					cos = Math.cos(angle),
					nextX = this.nextX * cos - this.nextZ * sin,
					nextZ = this.nextZ * cos + this.nextX * sin,
					x = this.x * cos - this.z * sin,
					z = this.z * cos + this.x * sin;

				this.nextX = nextX;
				this.nextZ = nextZ;
				this.x = x;
				this.z = z;
			},
			rotateZ: function (angle) {
				var sin = Math.sin(angle),
					cos = Math.cos(angle),
					nextX = this.nextX * cos - this.nextY * sin,
					nextY = this.nextY * cos + this.nextX * sin,
					x = this.x * cos - this.y * sin,
					y = this.y * cos + this.x * sin;

				this.nextX = nextX;
				this.nextY = nextY;
				this.x = x;
				this.y = y;
			},
			getAxis3D: function () {
				this.vx += (this.nextX - this.x) * this.SPRING;
				this.vy += (this.nextY - this.y) * this.SPRING;
				this.vz += (this.nextZ - this.z) * this.SPRING;

				this.vx *= this.FRICTION;
				this.vy *= this.FRICTION;
				this.vz *= this.FRICTION;

				this.x += this.vx;
				this.y += this.vy;
				this.z += this.vz;

				return { x: this.x, y: this.y, z: this.z };
			},
			getAxis2D: function (theta) {
				var axis = this.getAxis3D(),
					scale = this.FOCUS_POSITION / (this.FOCUS_POSITION + axis.z);

				return { x: this.center.x + axis.x * scale, y: this.center.y - axis.y * scale, color: this.COLOR.replace('%hue', this.hue + theta) };
			}
		};
		$(function () {
			RENDERER.init(STRATEGY);
		});
	</script>
</body>

</html>